Finding the Fourth Proportional to 1,345.09, 2,015.89 and 1,085.21

Step by Step Solution

1. Step 1: Write the proportion equation
   1,345.09 : 2,015.89 = 1,085.21 : x
2. Step 2: Convert to fraction form
   1,345.09/2,015.89 = 1,085.21/x
3. Step 3: Cross multiply
   1,345.09x = 2,015.89 × 1,085.21
4. Step 4: Simplify right side
   1,345.09x = 2,187,663.99
5. Step 5: Solve for x
   x = 2,187,663.99/1,345.09
6. Step 6: Final answer
   x = 1,626.41